Ιmpact of sunitinib-induced hypothyroidism on survival of patients with metastatic renal cancer.

Sunitinib plays an important role in managing the metastatic renal cell cancer (mRCC). Sunitinib-induced hypothyroidism is a common side-effect of the drug. There have been attempts to link hypothyroidism with a better clinical outcome in sunitinib-treated (mRCC) patients. Our aim was to relate the impact of hypothyroidism to the survival of these patients.

We have evaluated 70 patients with mRCC that received sunitinib as a first line treatment. Thyroid-stimulating hormone (TSH) was measured at baseline, after 15 days of treatment (day-15) and at the end of the second cycle (day-75). Biomarker data and correlations with response were analysed with Microsoft Excel. Comparison results from Student's t-test with a p less than 0.05 were considered statistically significant. Kaplan-Meyer and log-rank tests were performed using GraphPad Prism 5 for Windows.

Regarding the response to treatment, a progression-free survival (PFS) of 9.47 months and an overall survival (OS) of 22.03 months were demonstrated. Our data are consistent with published data by other authors. On day-15 from the beginning of the treatment an important number of patients exhibited a TSH elevation. On day-15 42.86% had a TSH over the upper normal limit and 50.0% at the end of the second cycle (day-75). TSH increased earlier in patients that exhibited an objective response (× 3.33 times the baseline values on day-15) than patients that exhibited disease stabilisation (× 2.18) or disease progression (× 1.59). Early increases in TSH were associated with a longer PFS (11.92 vs. 8.82 months, p = 0.0476) and a longer OS (3.10 vs. 1.08 years, p = 0.0011).

Early TSH-increase is associated with a clinical benefit. The patients that showed at least a twofold increase of their baseline TSH, responded to therapy by stabilisation or by regression of disease. This is the only study to our knowledge which shows that early increases - 2 weeks from starting the treatment - in TSH levels have a prognostic value. Both PFS and OS of the patients who demonstrated a higher than a twofold rise were significantly longer than the PFS and the OS of the patients that presented a lower or no TSH-increase.

BMC cancer. 2019 Apr 30*** epublish ***

Theofanis Vasileiadis, Michail Chrisofos, Michail Safioleas, Konstantinos Kontzoglou, Konstantinos Papazisis, Athina Sdrolia

Theagenion Cancer Hospital, Al. Symeonidi 2, 54007, Thessaloniki, Greece. ., Urology Department, Αttikon Hospital, Rimini 1, Chaidari, 124 62, Athens, Greece., 2nd Department of Propedeutic Surgery, Laiko Hospital, Agiou Thoma 17, 115 27, Athens, Greece., School of Medicine, National Kapodistrian University of Athens, 157 72, Athens, Greece., Theagenion Cancer Hospital, Al. Symeonidi 2, 54007, Thessaloniki, Greece.